Sculpt/dyntopo: Make the omp threads configurable to overcome performance issues

- autodetect optimal default, which typically avoids HT threads
- can store setting in .blend per scene
- this does not touch general omp max threads, due i found other areas where the calculations are fitting for huge corecount
- Intel notes, some of the older generation processors with HyperThreading would not provide significant performance boost for FPU intensive applications. On those systems you might want to set OMP_NUM_THREADS = total number of cores (not total number of hardware theads).

1 files changed, 10 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/scene.c b/source/blender/blenkernel/intern/scene.c
index 28cc4305da8..02bc1fcb699 100644
--- a/source/blender/blenkernel/intern/scene.c
+++ b/source/blender/blenkernel/intern/scene.c
@@ -638,6 +638,9 @@ Scene *BKE_scene_add(Main *bmain, const char *name)
 
 	sce->gm.exitkey = 218; // Blender key code for ESC
 
+	sce->omp_mode = SCE_OMP_AUTO;
+	sce->omp_num_threads = 1;
+
 	sound_create_scene(sce);
 
 	/* color management */
@@ -1868,3 +1871,10 @@ int BKE_scene_num_threads(const Scene *scene)
 	return BKE_render_num_threads(&scene->r);
 }
 
+int BKE_scene_num_omp_threads(const struct Scene *scene)
+{
+	if (scene->omp_mode == SCE_OMP_AUTO)
+		return BLI_omp_thread_count();
+	else
+		return scene->omp_num_threads;
+}